Various low-powered operating modes for extending battery life are known in notebook computers and hand-held devices. A sleep mode (also known as a "suspend" mode) permits a user to press a button which places the computer in a very low power configuration in which program execution is suspended. When the button is depressed a second time, the computer resumes execution from the point at which the button was depressed the first time. In some power-conserving operating modes, a computer will enter a sleep mode automatically if there has been no user activity within a defined interval.
In other efforts to extend battery life, computer circuits have been developed which provide reasonable computational speed when operated at reduced voltages. It is fair to say, however that no existing notebook computer offers the combined advantages of low power and high speed.
What is needed is a notebook computer that can operate at extremely low power levels when battery life is at a premium--such as during a long distance flight--and can operate at high speed when computational power is required. The current solution to this problem is to use two computers--a low-powered notebook for an extended flight, and a high-powered notebook or desktop computer for heavy number crunching.